sidelight

1. A light found at the side of something; especially of a vehicle.

   If it starts getting misty, put your sidelights on.

2. A light found at the side of something; especially of a vehicle.

   (broadly)(nautical) Red and green navigation lights indicating each side of a ship for collision avoidance; red on the port (left) and green on the starboard.

   light carried by a boat that indicates the boat's direction; vessels at night carry a red light on the port bow and a green light on the starboard bow

3. A window found at one or both sides of a door.

4. A piece of incidental information that helps one understand a subject.

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• sidelight Examples of sidelights